Clinical trial · Interventional
Therapeutic Dose Monitoring (TDM) of Tamoxifen
Therapeutic Dose Monitoring (TDM) of Tamoxifen and Its Active Metabolites in Combination With Patient-reported Symptom Scores Among Patients With Breast Cancer Receiving Adjuvant Tamoxifen Treatment
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
Tamoxifen is a potent and effective drug reducing the risk of dying from breast cancer in the adjuvant setting. Although more modern drugs have partly replaced tamoxifen, it is helpful in the neoadjuvant and metastatic settings as a single drug. Despite that, in the adjuvant setting, it is a valuable drug. This study aims to validate and study the feasibility of serial assessments, including therapeutic drug monitoring of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen by capillary blood sampling, combined with patient-reported symptom scores. This will provide preliminary data to allow us to develop a future multicentre randomised clinical trial of personalised dose monitoring and adjustment of adjuvant tamoxifen therapy to enhance the quality of life and breast cancer outcomes.
Conditions
Conditions (5)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Breast Cancer | Malignant Breast Neoplasm | CURATED_EXACT | 0.92 |
| Breast Carcinoma | Breast Carcinoma | ONTOLOGY_EXACT | 0.98 |
| Breast Tumors | Breast Neoplasm | ALIAS | 0.90 |
| Cancer of Breast | Malignant Breast Neoplasm | CURATED_EXACT | 0.92 |
| Malignant Neoplasm of Breast | Malignant Breast Neoplasm | ALIAS | 0.90 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Tamoxifen 20 mg | Drug | Tamoxifen | ALIAS |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- 0
- description
- Blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen will be measured.
- interventionNames
- Drug: Tamoxifen 20 mg
Primary outcomes (2)
- measure
- To validate the rhelise™ kit for monitoring tamoxifen, 4-hydroxytamoxifen and Z-endoxifen among patients recommended or who have ongoing adjuvant tamoxifen.
- timeFrame
- At at inclusion (baseline) for each participant.
- description
- Blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen at baseline, two weeks, 1, 2, and 3 weeks by capillary and venous blood sampling (whole blood/plasma).
- measure
- To validate the rhelise™ kit for monitoring tamoxifen, 4-hydroxytamoxifen and Z-endoxifen among patients recommended or who have ongoing adjuvant tamoxifen.
- timeFrame
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion Criteria: 1. Female patients aged ≥ 18 years with hormone-positive stage 0-3 breast cancer. 2. Performance status ECOG 0-2. 3. Ongoing daily adjuvant tamoxifen minimum of 2 months ± GnRH analogues ± RT for stage 3 breast cancer. 4. Locally recurrent disease, previously treated with adjuvant tamoxifen. 5. Able to use software applications developed specifically for small, wireless computing devices, such as smartphones and tablets. 6. Have small, wireless computing devices, such as smartphones and tablets. Exclusion Criteria: 1. Fulfilling any of the contraindications for tamoxifen. 2. Metastatic (stage IV) breast cancer. 3. Included in other clinical studies receiving not approved investigational medicinal drug. 4. Ongoing pregnancy or lactation. 5. Any psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule.
References
Publications (14)
- BACKGROUNDEarly Breast Cancer Trialists' Collaborative Group (EBCTCG); Davies C, Godwin J, Gray R, Clarke M, Cutter D, Darby S, McGale P, Pan HC, Taylor C, Wang YC, Dowsett M, Ingle J, Peto R. Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials. Lancet. 2011 Aug 27;378(9793):771-84. doi: 10.1016/S0140-6736(11)60993-8. Epub 2011 Jul 28. PMID 21802721
- BACKGROUNDEarly Breast Cancer Trialists' Collaborative Group (EBCTCG). Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials. Lancet. 2015 Oct 3;386(10001):1341-1352. doi: 10.1016/S0140-6736(15)61074-1. Epub 2015 Jul 23. PMID 26211827
- BACKGROUNDEriksson M, Eklund M, Borgquist S, Hellgren R, Margolin S, Thoren L, Rosendahl A, Lang K, Tapia J, Backlund M, Discacciati A, Crippa A, Gabrielson M, Hammarstrom M, Wengstrom Y, Czene K, Hall P. Low-Dose Tamoxifen for Mammographic Density Reduction: A Randomized Controlled Trial. J Clin Oncol. 2021 Jun 10;39(17):1899-1908. doi: 10.1200/JCO.20.02598. Epub 2021 Mar 18. PMID 33734864
- BACKGROUNDHe W, Fang F, Varnum C, Eriksson M, Hall P, Czene K. Predictors of Discontinuation of Adjuvant Hormone Therapy in Patients With Breast Cancer. J Clin Oncol. 2015 Jul 10;33(20):2262-9. doi: 10.1200/JCO.2014.59.3673. Epub 2015 Jun 1. PMID 26033800
- BACKGROUNDMadlensky L, Natarajan L, Tchu S, Pu M, Mortimer J, Flatt SW, Nikoloff DM, Hillman G, Fontecha MR, Lawrence HJ, Parker BA, Wu AH, Pierce JP. Tamoxifen metabolite concentrations, CYP2D6 genotype, and breast cancer outcomes. Clin Pharmacol Ther. 2011 May;89(5):718-25. doi: 10.1038/clpt.2011.32. Epub 2011 Mar 23. PMID 21430657
- BACKGROUNDFabian CJ. Will a Low-Dose Option Improve Uptake of Tamoxifen for Breast Cancer Risk Reduction? J Clin Oncol. 2019 Jul 1;37(19):1595-1597. doi: 10.1200/JCO.19.00656. Epub 2019 May 13. No abstract available.